Problem: You are given an unweighted tree with n vertices. Recall that a tree is a connected undirected graph without cycles.

Your task is to choose three distinct vertices a, b, c on this tree such that the number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c is the maximum possible. See the notes section for a better understanding.

The simple path is the path that visits each vertex at most once.

Input

The first line contains one integer number n (3 ≤ n ≤ 2 ⋅ 10^5) — the number of vertices in the tree. 

Next n - 1 lines describe the edges of the tree in form a_i, b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i). It is guaranteed that given graph is a tree.

Output

In the first line print one integer res — the maximum number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c.

In the second line print three integers a, b, c such that 1 ≤ a, b, c ≤ n and a ≠, b ≠ c, a ≠ c.

If there are several answers, you can print any.

Example

Input


8
1 2
2 3
3 4
4 5
4 6
3 7
3 8


Output


5
1 8 6

Note

The picture corresponding to the first example (and another one correct answer):

<image>

If you choose vertices 1, 5, 6 then the path between 1 and 5 consists of edges (1, 2), (2, 3), (3, 4), (4, 5), the path between 1 and 6 consists of edges (1, 2), (2, 3), (3, 4), (4, 6) and the path between 5 and 6 consists of edges (4, 5), (4, 6). The union of these paths is (1, 2), (2, 3), (3, 4), (4, 5), (4, 6) so the answer is 5. It can be shown that there is no better answer.

Solution (in JAVA):

Solution:
//package learning;
import java.util.*;
import java.io.*;
import java.lang.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class NitsLocal {
    static ArrayList<String> s1;
    static boolean[] prime;
    static int n = (int)1e7;
    
     static void sieve() {
Arrays.fill(prime	, true);
prime[0] = prime[1] = false;
for(int i = 2 ; i * i <= n ; ++i) {
if(prime[i]) {
for(int k = i * i; k<= n ; k+=i) {
prime[k] = false;
}
}
}
 
}
    public static void main(String[] args) {
        InputReader sc = new InputReader(System.in);
        n *= 2;
           prime  = new boolean[n + 1];
           //sieve();
                prime[1] = false;
              
                  
             /*    
        int n = sc.ni();
        int k = sc.ni();
        int []vis = new int[n+1];
        int []a = new int[k];
        for(int i=0;i<k;i++)
        {
            a[i] = i+1;
        }
        int j = k+1;
        int []b = new int[n+1];
        for(int i=1;i<=n;i++)
        {
            b[i] = -1;
        }
        int y = n - k +1;
        int tr = 0;
        int y1 = k+1;
        while(y-- > 0)
        {
        System.out.print("? ");
        for(int i=0;i<k;i++)
        {
            System.out.print(a[i] + " ");
        }
        
        System.out.flush();
        int pos = sc.ni();
        int a1 = sc.ni();
        b[pos] = a1;
        
        
        for(int i=0;i<k;i++)
        {
            if(a[i] == pos)
            {
                a[i] = y1;
                y1++;
            }
        }
        }
        ArrayList<Integer> a2 = new ArrayList<>();
        if(y >= k)
        {
            
        int c = 0;
        int k1 = 0;
            for(int i=1;i<=n;i++)
            {
                if(b[i] != -1)
                {
                    c++;
                    a[k1] = i;
                    a2.add(b[i]);
                    k1++;
                }
                if(c==k)
                    break;
            }
            
            Collections.sort(a2);
            System.out.print("? ");
        for(int i=0;i<k;i++)
        {
            System.out.print(a[i] + " ");
        }
        System.out.println();
        System.out.flush();
        int pos = sc.ni();
        int a1 = sc.ni();
        int ans = -1;
        for(int i=0;i<a2.size();i++)
        {
            if(a2.get(i) == a1)
            {
                ans = i+1;
                break;
            }
        }
        System.out.println("!" + " " + ans);
           System.out.flush();  
        }
        else
        {
            int k1 = 0;
            a = new int[k];
             for(int i=1;i<=n;i++)
            {
                if(b[i] != -1)
                {
                    
                    a[k1] = i;
                    a2.add(b[i]);
                    k1++;
                }
             
            }
              for(int i=1;i<=n;i++)
            {
                if(b[i] == -1)
                {
                    
                    a[k1] = i;
                    
                    k1++;
                    if(k1==k)
                        break;
                }
             
            }
              int ans = -1;
              while(true)
              {
                   System.out.print("? ");
                     for(int i=0;i<k;i++)
                   {
                         System.out.print(a[i] + " ");
                  }
                   System.out.println();
                   System.out.flush();
                   int pos = sc.ni();
                   int a1 = sc.ni();
                   int f = 0;
                   
                   if(b[pos] != -1)
                   {
                       Collections.sort(a2);
                       for(int i=0;i<a2.size();i++)
                       {
                           if(a2.get(i) == a1)
                           {
                               ans = i+1;
                               f = 1;
                               System.out.println("!" + " " + ans);
                               System.out.flush();
                               break;
                           }
                       }
                       if(f==1)
                           break;
                   }
                   else
                   {
                       b[pos] = a1;
                        a = new int[k];
                        a2.add(a1);
             for(int i=1;i<=n;i++)
            {
                if(b[i] != -1)
                {
                    
                    a[k1] = i;
                    a2.add(b[i]);
                    k1++;
                }
             
            }
              for(int i=1;i<=n;i++)
            {
                if(b[i] == -1)
                {
                    
                    a[k1] = i;
                    
                    k1++;
                    if(k1==k)
                        break;
                }
             
            }
                       
                   }
              }
        }  
          */
             /*
       int t = sc.ni();
             while(t-- > 0)
             {
                 int n = sc.ni();
                 int []a = sc.nia(n);
                 long sum = 0;
                 hm = new HashMap<>();
                 int d = 0;
                 for(int i=0;i<n;i++)
                 {
                     sum += (long) a[i];
                     if(sum < 0)
                     {
                         d = -1;
                     }
                     
                 }
                  l = 0;
                 r = 0;
                 f = 0;
                
                 long temp = maxSubArraySum(a,n,sum);
                 //w.println(temp + " " +f);
                
                if(f == -2)
                {
                   w.println("NO");
                }
                else
                {
                    w.println("YES");
                }
             }
               
           */
                 int n = sc.ni();
                 a = new ArrayList[n+1];
                 vis = new boolean[n+1];
                 level = new int[n+1];
                 parent = new int[n+1];
                 for(int i=1;i<=n;i++)
                 {
                     a[i] = new ArrayList<>();
                 }
                 int root = -1;
                   for(int i=0;i<n-1;i++)
                   {
                       int u = sc.ni();
                       if(root == -1)
                       root = u;
                       int v = sc.ni();
                       a[u].add(v);
                       a[v].add(u);
                   }
                
             bfs(root);
               int ans = -1;
               int max = -1;
               for(int i=1;i<=n;i++)
               {
                   max = Math.max(max,level[i]);
               }
               int ans1 = -1;
               int res1 = -1;
               int res2 = -1;
               int ans2 = -1;
               int f = 0;
               for(int i=1;i<=n;i++)
               {
                   if(level[i] == max)
                   {
                       
                           ans = i;
                           break;
                      
                   }
                   
               }
              level = new int[n+1];
              vis = new boolean[n+1];
              parent = new int[n+1];
              max = -1;
              bfs(ans);
              int y = -1;
              int diam = 0;
               for(int i=1;i<=n;i++)
               {
                   max = Math.max(max,level[i]);
               }
               diam = max;
                for(int i=1;i<=n;i++)
                  {
                      if(level[i] == diam-1)
                      {
                          ans2 = i;
                          break;
                      }
                  }
              for(int i=1;i<=n;i++)
               {
                   if(level[i] == max)
                   {
                       
                          y = i;
                           break;
                      
                   }
                   
               }
               temp = new boolean[n+1];
               temp[y] = true;
               ans1= y;
               int z = y;
                 while(z!=parent[z])
               {
                   temp[parent[z]] = true;
                   z = parent[z];
               }
               //w.println(parent[3]);
               vis =new boolean[n+1];
               int min = 0;
               while(y!=parent[y])
               {
                  
                   //level = new int[n+1];
                   Student t1 = bfs1(y,parent[y]);
                    
                   if(min < t1.id)
                   {
                       min = t1.id;
                       ans2 = t1.b;
                   }
                   //w.print(ans2 + " ");
                
                   y = parent[y];
               }
             temp[parent[y]] = true;
            
             
               
                
               
               res1 = ans1;
               res2 = ans2;
              
                 
              
    
               w.println(diam+min);
               w.println(ans + " " + res1 + " " +res2);
               
   
       w.close();
       
        
    }
   static int []level;
   static boolean []vis;
   static int []parent;
   static ArrayList<Integer> []a;
   static boolean []temp;
   static Student bfs1(int s,int p)
   {
      vis[s] = true;
     level[s] = 0;
     int max = 0;
     int ind = -1;
    // parent[s] = p;
     Queue<Integer> q = new LinkedList<>();
     q.add(s);
     while(q.size() > 0)
     {
          int cc = q.poll();
          
            //ArrayList<Integer> te= new ArrayList<>();
            Iterator itr = a[cc].iterator();
            while(itr.hasNext())
            {
                Integer e = (Integer) itr.next();
                //w.print(e + " ");
                 
                if(!vis[e] && e != parent[cc] && !temp[e])
                {
                  
                  q.add(e);
                  
                    level[e] = level[cc]+1;
                    vis[e] = true;
                    if(max < level[e])
                    {
                        max = level[e];
                        ind = e;
                    }
                    max = Math.max(max,level[e]);
                   
                    //parent[e] = cc;
                }
            }
     
                  
     
                  
     }
     return new Student(max,ind);
   }
   
   
 static void bfs(int s)
 {
     vis[s] = true;
     level[s] = 0;
     parent[s] = s;
     Queue<Integer> q = new LinkedList<>();
     q.add(s);
     while(q.size() > 0)
     {
          int cc = q.poll();
          
            //ArrayList<Integer> te= new ArrayList<>();
            Iterator itr = a[cc].iterator();
            while(itr.hasNext())
            {
                Integer e = (Integer) itr.next();
                //w.print(e + " ");
                 
                if(!vis[e])
                {
                    
                  q.add(e);
                  
                    level[e] = level[cc]+1;
                    vis[e] = true;
                    parent[e] = cc;
                }
            }
     
                  
     }
 }
     static int upperBound(ArrayList<Integer> a, int low, int high, int element){
    while(low < high){
        int middle = low + (high - low)/2;
        if(a.get(middle) > element)
            high = middle;
        else 
            low = middle + 1;
    }
    return low;
}
   static long func(long t,long e,long h,long a, long b)
   {
       if(e*a >= t)
           return t/a;
       else
       {
           return e + Math.min(h,(t-e*a)/b);
       }
   }
         
      
    public static int upperBound(int []arr,int n,int num)
    {
        int l = 0;
        int r = n;
        while(l < r)
        {
            int mid = (l+r)/2;
            if(num >= arr[mid])
            {
                l = mid +1;
            }
            else
                r = mid;
        }
        return l;
    }
    public static int countSetBits(int number){
        int count = 0;
        while(number>0){
            ++count;
            number &= number-1;
        }
        return count;
    }
    
     
      
 
    
    static HashSet<Integer> fac;
    public static void primeFactors(int n) 
    { 
        // Print the number of 2s that divide n 
        int t = 0;
        while (n%2==0) 
        { 
            fac.add(2);
            n /= 2; 
        } 
  
        // n must be odd at this point.  So we can 
        // skip one element (Note i = i +2) 
        for (int i = 3; i*i <= n; i+= 2) 
        { 
            // While i divides n, print i and divide n 
            while (n%i == 0) 
            { 
                fac.add(i);
                n /= i; 
            } 
        } 
  
        // This condition is to handle the case whien 
        // n is a prime number greater than 2 
        if (n > 2) 
            fac.add(n);
    } 
     static long modexp(long x,long n,long M)
{
    long power = n;
    long result=1;
    x = x%M;
    while(power>0)
    {
        if(power % 2 ==1)
            result=(result * x)%M;
        x=(x*x)%M;
        power = power/2;
    }
    return result;
}
      static long modInverse(long A,long M)
{
    return modexp(A,M-2,M);
}
    static long gcd(long a,long b)
    {
        if(a==0)
            return b;
        else
            return gcd(b%a,a);
    }
    static class Temp{
        int a;
        int b;
        int c;
        int d;
      
        Temp(int a,int b,int c,int d)
        {
            this.a = a;
            this.b = b;
            this.c  =c;
            this.d = d;
            //this.d = d;
        }
    }
   
    
    
   static long sum1(int t1,int t2,int x,int []t)
   {
       int mid = (t2-t1+1)/2;
  if(t1==t2)
      return 0;
    
   else
   return sum1(t1,mid-1,x,t) + sum1(mid,t2,x,t);
    
     
   }
  
   
    static String replace(String s,int a,int n)
    {
        char []c = s.toCharArray();
        for(int i=1;i<n;i+=2)
        {
            int num = (int) (c[i] - 48);
            num += a;
            num%=10;
            c[i] = (char) (num+48);
        }
        return new String(c);
    }
    static String move(String s,int h,int n)
    {
        h%=n;
        char []c = s.toCharArray();
        char []temp = new char[n];
        for(int i=0;i<n;i++)
        {
            temp[(i+h)%n] = c[i];
        }
        return new String(temp);
    }
    
     public static int ip(String s){
return Integer.parseInt(s);
}
     static class multipliers implements Comparator<Long>{
  
         
  public int compare(Long a,Long b) {
   if(a<b)
    return 1;
   else if(b<a)
    return -1;
   else
    return 0;
  }
 }
     
     static class multipliers1 implements Comparator<Student>{
  
  public int compare(Student a,Student b) {
   if(a.id<b.id)
    return -1;
   else if(b.id<a.id)
    return 1;
   else
   {
       if(a.b < b.b)
           return -1;
       else if(b.b<a.b)
           return 1;
       else
           return 0;
           
    //return 0;
   }
  }

 }

    // Java program to generate power set in 
// lexicographic order. 
 
    
    
    
      static class InputReader {
 
private final InputStream stream;
private final byte[] buf = new byte[8192];
private int curChar, snumChars;
 
public InputReader(InputStream st) {
this.stream = st;
}
 
public int read() {
if (snumChars == -1)
throw new InputMismatchException();
if (curChar >= snumChars) {
curChar = 0;
try {
snumChars = stream.read(buf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (snumChars <= 0)
return -1;
}
return buf[curChar++];
}
 
public int ni() {
int c = read();
while (isSpaceChar(c)) {
c = read();
}
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
int res = 0;
do {
res *= 10;
res += c - '0';
c = read();
} while (!isSpaceChar(c));
return res * sgn;
}
 
public long nl() {
int c = read();
while (isSpaceChar(c)) {
c = read();
}
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
long res = 0;
do {
res *= 10;
res += c - '0';
c = read();
} while (!isSpaceChar(c));
return res * sgn;
}
 
public int[] nia(int n) {
int a[] = new int[n];
for (int i = 0; i < n; i++) {
a[i] = ni();
}
return a;
}
 
public String rs() {
int c = read();
while (isSpaceChar(c)) {
c = read();
}
StringBuilder res = new StringBuilder();
do {
res.appendCodePoint(c);
c = read();
} while (!isSpaceChar(c));
return res.toString();
}
 
public String nextLine() {
int c = read();
while (isSpaceChar(c))
c = read();
StringBuilder res = new StringBuilder();
do {
res.appendCodePoint(c);
c = read();
} while (!isEndOfLine(c));
return res.toString();
}
 
public boolean isSpaceChar(int c) {
return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
}
 
private boolean isEndOfLine(int c) {
return c == '\n' || c == '\r' || c == -1;
}
 
}
 
 
 
 
 
   
static PrintWriter w = new PrintWriter(System.out);
                  static class Student
    {
        int id;
        //int x;
       
       int b;
      
        //long z;
        
        Student(int id,int b)
        {
            this.id = id;
            //this.x = x;
            //this.s = s;
            this.b = b;
          
           // this.z = z;
            
            
            
           
        }
        
    }
}